Hi. I have a 98 accord 4 cyl. Wouldnt pass smog due to couldnt stabilize vehicle. I bought a new iac and installed. The car now has a hiccup in it i cant get out. After warming up the car will"faint" for a sec then come back to life. It does it every few seconds. When its doing this if i stand on the gas peddle it sounds choked. ?

 

Honda idle control system doesn't like to have air in the cooling system - also vacuum leaks can confuse the system.
Check out this thread.
https://www.hondaaccordforum.com/for...e-speed-38734/

Idle problems caused by any of the things I listed, or caused by ad-hoc adjustment procedures seem to be a lot more common than a failed IACV.

 

thx for replying. I followed the instructions in the link, With iac unpluged, i turned the idle adjust screw all the way (after trying 1/4 turn incroments) both ways and it did nothing to the idle.engine F23B

 

In that case, here's what I would check...

1. Turning the screw did nothing, but is the idle too high or too low? If it's too low, take the idle adjustment screw all the way out & spray carb-cleaner in the hole to clear out the passages. Also check the O-ring around that screw whether it's hardened by age & heat & not sealing properly.

2. If it's too high, that sounds like a vacuum leak somewhere, so keep looking for it. Look at intake manifold gaskets, and even the O-rings around injectors where they stick into the manifold. Sometimes a vacuum leak makes a whistling sound at idle when the vacuum is strongest.

3. How about the throttle plate in the TB? Is it dirty around where the plate closes against the bore? Is it sticking just a bit open? Held open by a throttle cable that's been tightened by a misguided mechanic?

4. I know I said never to adjust the mechanical stop for the throttle, but what if a former mechanic used that to try adjusting the idle?